McGinnis played for the Indiana Pacers of the A.B.A. from 1971 to 1975, winning the M.V.P. award in 1975 along with Julius Erving when he led the league in scoring. He then went to the Philadelphia 76ers of the N.B.A. and also played for the Denver Nuggets, before returning to finish his career with pacers from 1980 to '82. McGinnis played in three A.B.A. all-star games (1973-'75) and three N.B.A. all-star games (1976, '77 & '79).